JP6110244B2 - Conductive adhesive tape, method for connecting conductive adhesive tape, solar cell module, and method for manufacturing the same - Google Patents

Description

  The present invention relates to a conductive adhesive tape, a method for connecting a conductive adhesive tape, a solar cell module, and a method for manufacturing the same.

  Solar cells are expected as new energy sources because they directly convert clean and inexhaustible sunlight into electricity.

The solar cell is used as a solar cell module in which a plurality of solar cells are connected via tab wires.
The conventional tab wire used the type which solder-coated on the copper wire surface. However, since a high temperature is required for solder connection, panel breakage and warpage of the light receiving surface, short-circuit due to solder protruding from the tab wire (leakage), etc. occurred, causing problems.
Therefore, a conductive adhesive has been used as a connection material instead of solder. Examples of the tab wire coated with the conductive adhesive include a conductive adhesive tape (tab wire) coated with the conductive adhesive on the entire surface of a copper wire. Since such a tab wire can be connected at a low temperature, it is possible to reduce the problem of warping or cracking of the solar battery cell.

As the use of solar cell modules expands, there is a need for a solar cell module manufacturing method that is inexpensive and capable of mass production. One of them is a roll-to-roll system (hereinafter sometimes abbreviated as “RtoR system”).
For example, a film forming apparatus for an organic thin film solar cell in which a plurality of desired organic thin films are sequentially stacked on a long object to be used for a roll-to-roll method has been proposed (for example, a patent) Reference 1).

  The conductive adhesive tape is generally manufactured with a specific length such as about 100 m. Therefore, even when trying to manufacture a product batch exceeding the length of the conductive adhesive tape using the RtoR method when manufacturing the solar cell module, the length of the conductive adhesive tape limits the length of the product batch. May end up.

  In order to obtain a long conductive adhesive tape, for example, a method of manufacturing a long conductive adhesive tape by joining two or more conductive adhesive tapes has been proposed (for example, Patent Document 2 and 3). However, with these proposed techniques, the length of the conductive adhesive tape can be increased, but it cannot be applied to the RtoR method when manufacturing a solar cell module.

  Therefore, a conductive adhesive tape connecting method for obtaining a long conductive adhesive tape having a desired length that can be used for manufacturing a solar cell module by a roll-to-roll method, and a conductive property obtained by the connecting method. There is a need to provide an adhesive tape, a method of manufacturing a solar cell module by a roll-to-roll method using a connected conductive adhesive tape, and a solar cell module obtained by the method of manufacturing the solar cell module. is the current situation.

JP 2012-238661 A JP 2010-287901 A JP 2008-156126 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides a conductive adhesive tape connecting method for obtaining a long conductive adhesive tape of a desired length that can be used for manufacturing a solar cell module by a roll-to-roll method, and the connection method. Provided are a conductive adhesive tape to be obtained, a method for manufacturing a solar cell module by a roll-to-roll method using a connected conductive adhesive tape, and a solar cell module obtained by the method for manufacturing the solar cell module. For the purpose.

Means for solving the problems are as follows. That is,
<1> A method for connecting a conductive adhesive tape including a connecting step of connecting one end portion in the longitudinal direction of the first conductive adhesive tape and one end portion in the longitudinal direction of the second conductive adhesive tape. Because
The first conductive adhesive tape includes a metal first conductive base material, a first adhesive layer containing an adhesive, and a first release film that can be peeled off from the first adhesive layer. And in this order,
At the one end of the first conductive adhesive tape, the end of the first release film is outside the end of the first conductive adhesive tape in the longitudinal direction of the first adhesive layer. And the first adhesive layer side surface of the first release film is exposed,
The second conductive adhesive tape is a metal second conductive substrate, a second adhesive layer containing an adhesive, and a second release film that can be peeled off from the second adhesive layer. And in this order,
At the one end of the second conductive adhesive tape, the end of the second adhesive layer is outside the end of the second conductive adhesive tape in the longitudinal direction than the end of the second release film. And the second release film side surface of the second adhesive layer is exposed,
In the first connecting step, the first adhesive layer side surface of the first release film and the second adhesive layer side surface opposite to the second adhesive layer side of the first release film are bonded together. And the surface of the first conductive substrate opposite to the first adhesive layer side and the surface of the second adhesive layer on the second release film side are bonded together. It is a connection method of the conductive adhesive tape characterized by including a 2nd bonding process.
<2> The surface of the first release film opposite to the first adhesive layer side and the second release mold so that the first bonding process straddles the end of the first release film. It is the connection method of the conductive adhesive tape as described in said <1> performed by bonding an adhesive tape on the surface on the opposite side to the 2nd adhesive layer side of a film.
<3> In the second bonding process, the surface of the first conductive substrate on the side opposite to the first adhesive layer side and the surface of the second adhesive layer on the second release film side are bonded. <1> to <2>, wherein the lengths of the contact surfaces formed by combining the lengths in the longitudinal direction of the first conductive adhesive tape and the second conductive adhesive tape are 5 mm to 100 mm. The method for connecting a conductive adhesive tape according to any one of the above.
<4> A conductive adhesive tape obtained by the method for connecting a conductive adhesive tape according to any one of <1> to <3>.
<5> A method for manufacturing a solar cell module using a roll-to-roll method,
An arrangement step of disposing the conductive adhesive tape according to the above <4> from which the release film has been peeled, on the electrode of the solar battery cell,
A covering step of covering the solar battery cell with a sealing resin, and further covering the sealing resin with a moisture-proof backsheet;
A pressing step of pressing the moisture-proof backsheet;
It is a manufacturing method of the solar cell module characterized by including the heating process which heats the said photovoltaic cell.
<6> The solar cell module manufacturing method according to <5>, wherein the release film is peeled in the order of the second release film and the first release film in the arranging step.
<7> A solar cell module obtained by the method for producing a solar cell module according to any one of <5> to <6>.

  According to the present invention, it is possible to solve the above-mentioned problems in the related art, achieve the above-mentioned object, and have a long conductive property of a desired length that can be used for manufacturing a solar cell module by a roll-to-roll method. Method for connecting conductive adhesive tape to obtain adhesive tape, conductive adhesive tape obtained by the connection method, and method for manufacturing solar cell module by roll-to-roll method using connected conductive adhesive tape And providing a solar cell module obtained by the method for manufacturing the solar cell module.

FIG. 1 is a schematic cross-sectional view showing an example of an end portion of a first conductive adhesive tape used in the method for connecting a conductive adhesive tape of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of an end portion of a second conductive adhesive tape used in the method for connecting conductive adhesive tapes of the present invention. FIG. 3 is a schematic cross-sectional view for explaining an example of the connection process. FIG. 4 is a schematic cross-sectional view of a connection portion between the first conductive adhesive tape and the second conductive adhesive tape after an example of the method for connecting the conductive adhesive tape of the present invention is performed. FIG. 5 is a schematic cross-sectional view showing an example of peeling the release film from the conductive adhesive tape. FIG. 6 is a schematic view of an example of a roll-to-roll solar cell module manufacturing apparatus for performing the solar cell module manufacturing method of the present invention. FIG. 7 is a schematic view showing an example of a laminating apparatus for conductive adhesive tape in the solar cell module manufacturing apparatus of FIG. FIG. 8 is a schematic view of a test specimen when conducting resistance values. FIG. 9 is a schematic cross-sectional view of the connection location of the conductive adhesive tapes of Comparative Examples 1 and 2.

(Connection method of conductive adhesive tape and conductive adhesive tape)
The method for connecting a conductive adhesive tape of the present invention includes at least a connection step, and further includes other steps as necessary.
The conductive adhesive tape of the present invention is obtained by the method for connecting the conductive adhesive tape of the present invention.

<Connection process>
The connecting step is a step of joining one end portion in the longitudinal direction of the first conductive adhesive tape and one end portion in the longitudinal direction of the second conductive adhesive tape.
The connecting step includes at least a first bonding process and a second bonding process.

The first conductive adhesive tape includes a metal first conductive base material, a first adhesive layer containing an adhesive, and a first release film that can be peeled off from the first adhesive layer. And in this order.
The second conductive adhesive tape includes a metal second conductive substrate, a second adhesive layer containing an adhesive, and a second release film that can be peeled from the second adhesive layer. And in this order.

In the one end portion of the first conductive adhesive tape, the end of the first release film is outside in the longitudinal direction of the first conductive adhesive tape rather than the end of the first adhesive layer. It is in. And the said 1st adhesive layer side surface of the said 1st release film is exposed in the said one edge part of a said 1st electroconductive adhesive tape.
In the one end portion of the second conductive adhesive tape, the end of the second adhesive layer is outside in the longitudinal direction of the second conductive adhesive tape rather than the end of the second release film. It is in. The surface of the second adhesive layer on the second release film side is exposed at the one end of the second conductive adhesive tape.

<< First Bonding Process >>
In the first bonding process, the surface of the first release film on the first adhesive layer side and the surface of the second release film on the side opposite to the second adhesive layer side are used. It is a process of bonding.

  In the first bonding process, the surface of the first release film opposite to the first adhesive layer side and the second release film so as to straddle the end of the first release film. It is preferable to carry out by bonding an adhesive tape to the surface opposite to the second adhesive layer side of the mold film.

  In the first laminating process, the surface of the first release film on the first adhesive layer side and the surface of the second release film on the opposite side to the second adhesive layer side are It is the length of the contact surface formed by bonding, and there is no particular limitation on the length in the longitudinal direction of the first conductive adhesive tape and the second conductive adhesive tape, depending on the purpose. Although it can select suitably, 5 mm-100 mm are preferable and 10 mm-50 mm are more preferable from the point of bonding workability | operativity, adhesiveness, and electrical connectivity.

<< Second bonding process >>
The second laminating process includes a surface of the first conductive substrate on the side opposite to the first adhesive layer side, and a surface of the second adhesive layer on the second release film side. Is a process of pasting together.

  In the second bonding process, the surface of the first conductive substrate on the side opposite to the first adhesive layer side, and the surface of the second adhesive layer on the second release film side, Is the length of the contact surface formed by bonding, and the length in the longitudinal direction of the first conductive adhesive tape and the second conductive adhesive tape is not particularly limited and depends on the purpose. However, 5 mm to 100 mm is preferable and 10 mm to 50 mm is more preferable from the viewpoint of achieving both the conduction resistance at the connection location and the joining accuracy.

  There is no restriction | limiting in particular as an order of the said 1st bonding process in the said connection process, and a said 2nd bonding process, Although it can select suitably according to the objective, The said 2nd bonding It is preferable from the viewpoint of bonding workability to perform the first bonding process after the processing.

<<<< first conductive adhesive tape >>>>
The first conductive adhesive tape includes the first conductive base material, the first adhesive layer, and the first release film in this order.

-1st electroconductive base material-
As the first conductive substrate, if it is made of metal, its material, size and structure are not particularly limited and can be appropriately selected according to the purpose.

Examples of the material of the first conductive substrate include copper, aluminum, iron, gold, silver, nickel, palladium, chromium, molybdenum, and alloys thereof.
There is no restriction | limiting in particular as a shape of a said 1st electroconductive base material, According to the objective, it can select suitably, For example, flat form etc. are mentioned.
There is no restriction | limiting in particular as a structure of a said 1st electroconductive base material, According to the objective, it can select suitably, A single layer structure may be sufficient and a laminated structure may be sufficient. Examples of the single layer structure include a single layer structure made of copper, aluminum, or the like. Examples of the laminated structure include a laminated structure having a base material made of copper, aluminum or the like and a plating layer. Examples of the material of the plating layer include gold, silver, tin, and solder.

When the first conductive substrate is flat, the average thickness is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 μm to 200 μm, more preferably 10 μm to 150 μm. . When the average thickness is less than 10 μm, the extraction efficiency of electricity generated by the solar battery cells may be reduced, and when it exceeds 200 μm, connection reliability may be reduced. When the average thickness is within the more preferable range, it is advantageous in that connection reliability is more excellent.
The average thickness can be obtained, for example, by measuring the thickness of the first conductive substrate at any 10 points of the first conductive substrate and averaging the measured values.

  When the adhesive in the first adhesive layer is an insulating adhesive, the first conductive group is provided so that the first conductive base material can be electrically connected to the electrode on the solar battery cell. The surface of the material on the first adhesive layer side preferably has a protrusion.

  When the adhesive in the second adhesive layer is an insulating adhesive, the first conductive material can be connected to the first conductive substrate and the second conductive substrate. It is preferable that the surface on the opposite side to the said 1st contact bonding layer side of a base material has a processus | protrusion.

-First adhesive layer-
If it contains an adhesive agent as said 1st contact bonding layer, there will be no restriction | limiting in particular, According to the objective, it can select suitably.
Examples of the adhesive include a conductive adhesive and an insulating adhesive.

--Conductive adhesive--
The conductive adhesive is not particularly limited and may be appropriately selected depending on the purpose. For example, the conductive adhesive contains at least conductive particles, and preferably includes a film-forming resin, a curable resin, and a curing agent. A conductive adhesive containing other components as necessary is also included.

---- Conductive particles ---
The conductive particles are not particularly limited and may be appropriately selected depending on the purpose. For example, nickel particles, gold-coated nickel particles, resin particles with a resin core coated with Ni, and resin cores with Ni coated. Furthermore, resin particles whose outermost surface is coated with Au can be mentioned.

--- Film forming resin ---
There is no restriction | limiting in particular as said film formation resin, According to the objective, it can select suitably, For example, phenoxy resin, unsaturated polyester resin, saturated polyester resin, urethane resin, butadiene resin, polyimide resin, polyamide resin, polyolefin Resin etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, phenoxy resin is particularly preferable.

--- Curable resin ---
There is no restriction | limiting in particular as said curable resin, According to the objective, it can select suitably, For example, an epoxy resin, an acrylate resin, etc. are mentioned.
In the solar cell module, the curable resin may be cured by itself or may be cured by a curing agent described later.

--- Curing agent ---
The curable resin is preferably used in combination with a curing agent. There is no restriction | limiting in particular as said hardening | curing agent, According to the objective, it can select suitably, For example, imidazole represented by 2-ethyl 4-methylimidazole; Lauroyl peroxide, butyl peroxide, benzyl peroxide, Organic peroxides such as dilauroyl peroxide, dibutyl peroxide, benzyl peroxide, peroxydicarbonate and benzoyl peroxide; anionic curing agents such as organic amines; cations such as sulfonium salts, onium salts and aluminum chelators System curing agents and the like.
Among these, combinations of epoxy resins and imidazoles, and combinations of acrylate resins and organic peroxides are particularly preferable.

--- Other ingredients ---
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a silane coupling agent, a filler, a softener, an accelerator, anti-aging agent, a coloring agent (pigment, dye) , Organic solvents, ion catcher agents and the like. The addition amount of the other components is not particularly limited and can be appropriately selected depending on the purpose.

-Insulating adhesive-
The insulating adhesive is not particularly limited and may be appropriately selected depending on the purpose. For example, the insulating adhesive contains a film-forming resin, a curable resin, and a curing agent, and, if necessary, other Insulating adhesives containing these components may be mentioned.
The film-forming resin, the curable resin, the curing agent, and the other components in the insulating adhesive are not particularly limited and may be appropriately selected depending on the purpose. For example, the conductive adhesive Examples thereof include the film-forming resin, the curable resin, the curing agent, and the other components exemplified in the description of the agent.

There is no restriction | limiting in particular as average thickness of a said 1st contact bonding layer, Although it can select suitably according to the objective, 3 micrometers-100 micrometers are preferable, 5 micrometers-50 micrometers are more preferable, 10 micrometers-35 micrometers are especially preferable.
The average thickness can be obtained, for example, by measuring the thickness of the first adhesive layer at any 10 points of the first adhesive layer and averaging the measured values.

-First release film-
The first release film is not particularly limited as long as it is a film that can be peeled off from the first adhesive layer, and can be appropriately selected according to the purpose. For example, a release agent is provided on one side of the first release film. Examples thereof include a coated polyethylene terephthalate film.

  There is no restriction | limiting in particular as average thickness of a said 1st release film, Although it can select suitably according to the objective, 5 micrometers-100 micrometers are preferable, and 20 micrometers-50 micrometers are more preferable.

There is no restriction | limiting in particular as an average width | variety of a said 1st electroconductive adhesive tape, Although it can select suitably according to the objective, 0.5 mm-10 mm are preferable and 2 mm-5 mm are more preferable.
The average width can be obtained, for example, by measuring the width of the first conductive adhesive tape at any 10 points of the first conductive adhesive tape and averaging the measured values.

  There is no restriction | limiting in particular as the length of the longitudinal direction of a said 1st electroconductive adhesive tape, According to the objective, it can select suitably, For example, 50m-200m etc. are mentioned.

  In the one end portion of the first conductive adhesive tape, the end of the first release film is outside in the longitudinal direction of the first conductive adhesive tape rather than the end of the first adhesive layer. It is in. And the said 1st adhesive layer side surface of the said 1st release film is exposed in the said one edge part of a said 1st electroconductive adhesive tape.

  In the one end portion of the first conductive adhesive tape, it is preferable that the position of the end of the first conductive substrate coincides with the position of the end of the first adhesive layer.

  There is no restriction | limiting in particular as a manufacturing method of a said 1st electroconductive adhesive tape, According to the objective, it can select suitably, For example, an electroconductive base material, an adhesive layer, and a release film in this order. After producing the conductive adhesive tape which has, it can manufacture by removing the said conductive base material and the said adhesive layer of desired length in one edge part of the manufactured said conductive adhesive tape.

<<< Second conductive adhesive tape >>>
The second conductive adhesive tape includes the second conductive substrate, the second adhesive layer, and the second release film in this order.

  Examples of the material and shape of the second conductive base material, the second adhesive layer, and the second release film in the second conductive adhesive tape include the first conductive adhesive tape. Examples of the first conductive base material, the first adhesive layer, and the material and shape of the first release film exemplified in FIG.

It is preferable that the second conductive base material has the same material and the same average thickness as the first conductive base material.
It is preferable that the second adhesive layer has the same material and the same average thickness as the first adhesive layer.
The second release film is preferably the same material and the same average thickness as the first release film.

  There is no restriction | limiting in particular as an average width | variety of a said 2nd conductive adhesive tape, Although it can select suitably according to the objective, It is preferable that it is the same as the average width | variety of a said 1st conductive adhesive tape.

  There is no restriction | limiting in particular as the length of the longitudinal direction of a said 2nd conductive adhesive tape, According to the objective, it can select suitably, For example, 50m-200m etc. are mentioned.

  In the one end portion of the second conductive adhesive tape, the end of the second adhesive layer is outside in the longitudinal direction of the second conductive adhesive tape rather than the end of the second release film. It is in. The surface of the second adhesive layer on the second release film side is exposed at the one end of the second conductive adhesive tape.

  In the one end portion of the second conductive adhesive tape, it is preferable that the position of the end of the second conductive substrate coincides with the position of the end of the second adhesive layer.

  There is no restriction | limiting in particular as a manufacturing method of a said 2nd electroconductive adhesive tape, According to the objective, it can select suitably, For example, an electroconductive base material, an adhesive layer, and a release film in this order. After producing the electroconductive adhesive tape which has, it can manufacture by removing the said release film of desired length in one edge part of the produced said electroconductive adhesive tape.

An example of the method for connecting the conductive adhesive tape of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of an end portion of a first conductive adhesive tape used in the method for connecting a conductive adhesive tape of the present invention.
The first conductive adhesive tape 10 has a first release film 11, a first adhesive layer 12, and a first conductive base material 13 in this order. At one end of the first conductive adhesive tape 10, the end 11 a of the first release film is more outward in the longitudinal direction of the first conductive adhesive tape 10 than the end 12 a of the first adhesive layer. is there. And in the said one edge part of the 1st electroconductive adhesive tape 10, the surface 11b by the side of the 1st adhesive layer 12 of the 1st release film 11 is exposed.
The position of the end 13a of the first conductive substrate coincides with the position of the end 12a of the first adhesive layer.

FIG. 2 is a schematic cross-sectional view showing an example of an end portion of a second conductive adhesive tape used in the method for connecting conductive adhesive tapes of the present invention.
The second conductive adhesive tape 20 has a second release film 21, a second adhesive layer 22, and a second conductive base material 23 in this order. At one end of the second conductive adhesive tape 20, the end 22 a of the second adhesive layer is more outward in the longitudinal direction of the second conductive adhesive tape 20 than the end 21 a of the second release film. is there. The surface 22b of the second adhesive layer 22 on the second release film 21 side is exposed at the one end of the second conductive adhesive tape 20.
The position of the end 23a of the second conductive substrate coincides with the position of the end 22a of the second adhesive layer.

FIG. 3 is a schematic cross-sectional view for explaining an example of the connection process.
First, the surface 11b of the first release film 11 and the surface 21b of the second release film 21 (surface opposite to the second adhesive layer 22 side) are bonded together (first bonding process). .
Next, the surface 13b of the first conductive substrate 13 (surface opposite to the first adhesive layer 12 side) and the surface 22b of the second adhesive layer 22 (surface on the second release film 21 side) ) Are bonded together (second bonding process).
In an example of the first bonding process, the bonding between the surface 11 b and the surface 21 b is performed using the adhesive tape 111. For example, in the first bonding process, the surface 11b opposite to the first adhesive layer 12 side of the first release film 11 and the second surface so as to straddle the end 11a of the first release film 11. This is performed by adhering the adhesive tape 111 to the surface 21b of the release film 21 opposite to the second adhesive layer 22 side.
In an example of the second bonding process, the bonding between the surface 13b and the surface 22b is performed by heating. By heating, the second adhesive layer 22 is softened, and the surface 13b and the surface 22b are bonded together.
By doing so, a connection process is completed and the 1st conductive adhesive tape 10 and the 2nd conductive adhesive tape 20 are connected (FIG. 4).

  When the release films (the first release film and the second release film) are peeled from the conductive adhesive tape obtained by the conductive adhesive tape connecting method of the present invention, the first release Since the surface 11b of the mold film 11 and the surface 21b of the second release film 21 are in contact and bonded together, by peeling in the order of the second release film and the first release film, The connection part of a 1st mold release film and a 2nd mold release film leaves | separates, and the problem that one mold release film cannot peel does not arise (FIG. 5).

  According to the method for connecting conductive adhesive tapes of the present invention, a long conductive adhesive tape in which ends of a plurality of conductive adhesive tapes are joined can be manufactured. The length of the conductive adhesive tape to be manufactured can be arbitrarily set. In addition, there is no problem in conduction between the end portion of the first conductive adhesive tape and the end portion of the second conductive adhesive tape. Moreover, when peeling a release film, in the connection location (joint) of the edge part of a 1st conductive adhesive tape and the edge part of a 2nd conductive adhesive tape, the peeling remainder of a release film is Does not occur. Therefore, for example, the manufactured conductive adhesive tape can be used for manufacturing a solar cell module using a roll-to-roll method. At that time, the length of the conductive adhesive tape does not limit the length of the roll-to-roll manufacturing batch.

(Solar cell module manufacturing method and solar cell module)
The manufacturing method of the solar cell module of the present invention includes at least a disposing step, a covering step, a pressing step, and a heating step, and further includes other steps as necessary.
The method for manufacturing the solar cell module is a method for manufacturing a solar cell module using a roll-to-roll method.
The solar cell module of the present invention is manufactured by the method for manufacturing the solar cell module of the present invention.

<Arrangement process>
The placement step is not particularly limited as long as it is a step of placing the conductive adhesive tape of the present invention with the release film peeled off on the electrode of the solar battery cell, and can be appropriately selected according to the purpose. it can. Here, the conductive adhesive tape is an electrode for extracting power from the solar battery cell.
In the arrangement step, it is preferable that the release film is peeled in the order of the second release film and the first release film. By doing so, the connection part of a 1st release film and a 2nd release film leaves | separates, and the problem that one release film cannot peel does not arise, but a release film can be peeled reliably.

<< Solar cell >>
The solar battery cell is not particularly limited as long as it has electrodes, and can be appropriately selected according to the purpose.For example, the solar battery cell has at least a photoelectric conversion element as a photoelectric conversion unit, a finger electrode, and a bus bar electrode. Furthermore, it has other members as required.

  Examples of the solar battery cell include a thin film solar battery cell and a crystalline solar battery cell. Examples of the thin film solar cell include an amorphous silicon solar cell, a compound solar cell (CIS solar cell, CdS / CdTe solar cell), a dye-sensitized solar cell, and an organic thin film solar cell. And microcrystalline silicon solar cells (tandem solar cells). Examples of the crystalline solar battery cell include a single crystal silicon solar battery cell and a polycrystalline silicon solar battery cell.

  The solar battery cell may have a bus bar-less structure without a bus bar electrode.

  There is no restriction | limiting in particular as average thickness of the said photovoltaic cell, According to the objective, it can select suitably.

<Coating process>
The covering step is not particularly limited as long as it is a step of covering the solar battery cell with a sealing resin and further covering the sealing resin with a moisture-proof backsheet, and can be appropriately selected according to the purpose. it can.

<< Resin for sealing >>
The sealing resin is not particularly limited and may be appropriately selected depending on the purpose. For example, ethylene / vinyl acetate copolymer (EVA), ethylene / vinyl acetate / triallyl isocyanurate (EVAT), Examples include polyvinyl butyrate (PVB), polyisobutylene (PIB), silicone resin, polyurethane resin, and the like.

<< Dampproof Back Sheet >>
There is no restriction | limiting in particular as said moisture-proof backsheet, According to the objective, it can select suitably, For example, the laminated body of polyethylene terephthalate (PET), aluminum (Al), PET, Al, and polyethylene (PE) etc. Can be mentioned.

<Pressing step and heating step>
The pressing step is not particularly limited as long as it is a step of pressing the moisture-proof backsheet, and can be appropriately selected according to the purpose. The pressure to press and the time to press are arbitrary.

  The heating step is not particularly limited as long as it is a step of heating the solar battery cell, and can be appropriately selected according to the purpose. The sealing resin can also be heated by heating the solar battery cell. The conductive adhesive tape can also be heated.

  There is no restriction | limiting in particular as heating temperature in the said heating process, Although it can select suitably according to the objective, 50 to 250 degreeC is preferable and 100 to 200 degreeC is more preferable. When the heating temperature is less than 50 ° C., sealing may be insufficient, and when it exceeds 250 ° C., an organic resin contained in an adhesive, a sealing resin, or the like may be thermally decomposed. When the heating temperature is within the more preferable range, it is advantageous in terms of sealing reliability.

  There is no restriction | limiting in particular as the heating time in the said heating process, Although it can select suitably according to the objective, 1 second-1 hour are preferable, 5 seconds-30 minutes are more preferable, and 10 seconds-20 minutes are especially. preferable. If the heating time is less than 1 second, sealing may be insufficient. When the heating time is within the particularly preferable range, it is advantageous in terms of sealing reliability.

  There is no restriction | limiting in particular as an order which starts the said press process and the said heating process, According to the objective, it can select suitably.

FIG. 6 is a schematic view of an example of a roll-to-roll solar cell module manufacturing apparatus for performing the solar cell module manufacturing method of the present invention. An example of the manufacturing method of the solar cell module of the present invention will be described using this schematic diagram.
The solar cell module manufacturing apparatus of FIG. 6 has reels 40, 50, 60, 70, 90, a laminator device 80, transport rolls 42, 51, 82, and laminate rolls 52, 62, 72.
The reel 40 is wound with a flexible long sheet 34 that can be wound into a roll. On the elongate sheet 34, the photovoltaic cell which has a photoelectric conversion element, a finger electrode, and a bus-bar electrode is placed.
The reel 50 is wound with the conductive adhesive tape 30 of the present invention.
A tape-shaped sealing resin 35 is wound around the reel 60.
The reel 70 is wound with a tape-shaped moisture-proof back sheet 36.
The solar cells on the long sheet 34 fed out from the reel 40 are guided by the transport roll 42 and reach between the two laminate rolls 52. On the other hand, the conductive adhesive tape 30 delivered from the reel 50 is guided to the transport roll 51 and reaches between the two laminate rolls 52. The release film 31 is peeled off immediately before the conductive adhesive tape 30 reaches between the two laminate rolls 52. Between the two laminate rolls 52, the conductive adhesive tape 30 from which the release film 31 has been peeled is disposed on the electrode on the solar battery cell on the long sheet 34 (arrangement step).
Subsequently, the solar battery cell on the long sheet 34 that has passed through the laminate roll 52 reaches between the two laminate rolls 62. On the other hand, the tape-shaped sealing resin 35 fed from the reel 60 covers the solar cells on the long sheet 34 between the two laminate rolls 62. Further, the sealing resin 35 on the long sheet 34 that has reached between the two laminating rolls 72 is covered between the two laminating rolls 72 by the moisture-proof back sheet 36 sent out from the reel 70 (covering step).
Subsequently, the long sheet 34 passes through the laminator device 80. At this time, the moisture-proof back sheet 36 is pressed, and the solar cells, the conductive adhesive tape, the sealing resin 35 and the moisture-proof back sheet 36 on the long sheet 34 are further heated. By doing so, conduction between the solar battery cell and the conductive adhesive tape is ensured, and the solar battery cell is sealed with the sealing resin 35 (pressing process and heating process).
Subsequently, the long sheet 34 that has passed through the laminator device 80 is guided to the transport roll 82 and is taken up by the reel 90.

  In the case where a plurality of conductive adhesive tapes are arranged on the solar cells, the combination of the reel 50 and the transport roll 51 may be installed in accordance with the number of conductive adhesive tapes arranged on the solar cells. Good. At this time, the pair of laminating rolls 52 is not limited to the number of conductive adhesive tapes arranged on the solar battery cell, but may be one set or the same number of sets as the number of conductive adhesive tapes. May be.

In addition, in the manufacturing method of the solar cell module of the present invention, as another aspect, in the above manufacturing method, the long sheet 34 is cut by a solar cell module unit without being wound by a reel after passing the laminator device 80. May be.
Further, the sealing resin may seal only one side of the long sheet, or may seal both sides.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Connection of conductive adhesive tape>
A conductive substrate with an adhesive layer (DT101C4, manufactured by Dexerials Corporation) in which an adhesive layer with an average thickness of 15 μm was laminated on a copper foil (conductive substrate) with an average thickness of 35 μm was used.
A release-treated polyethylene terephthalate film (release film, average thickness 25 μm) was bonded onto the adhesive layer of the conductive substrate with the adhesive layer. By slitting this to have a width of 4 mm, two conductive adhesive tapes having a length of about 100 m in the longitudinal direction and a width of 4 mm were obtained. In the edge part of the obtained electroconductive adhesive tape, the terminal of the said conductive base material, the terminal of the said adhesive layer, and the terminal of the said release film corresponded.
One end of the obtained one conductive adhesive tape was processed so that the end of the release film was located outside the end of the adhesive layer in the longitudinal direction of the end of the adhesive layer. As a result, the surface of the release film on the adhesive layer side was exposed. Thus, a first conductive adhesive tape 10 having an end portion as shown in FIG. 1 was obtained.
Moreover, one end part of the obtained other conductive adhesive tape was processed so that the end of the adhesive layer was outside the longitudinal direction of the conductive adhesive tape with respect to the end of the release film. As a result, the surface of the adhesive layer on the release film side was exposed. In this way, the 2nd conductive adhesive tape 20 which has an edge part as shown in FIG. 2 was obtained.

Subsequently, the surface 11b of the first release film 11 and the surface 21b (surface opposite to the second adhesive layer 22 side) of the second release film 21 were bonded together (first bonding). processing).
Subsequently, the surface 13b of the first conductive substrate 13 (surface opposite to the first adhesive layer 12 side) and the surface 22b of the second adhesive layer 22 (surface on the second release film 21 side) ) Are bonded together (second bonding process).
In the first bonding process, the bonding between the surface 11b and the surface 21b was performed using an adhesive tape 111 (polyester film pressure-sensitive adhesive tape No. 631S, manufactured by Teraoka Seisakusho Co., Ltd.). That is, in the first bonding process, the surface 11b opposite to the first adhesive layer 12 side of the first release film 11 and the second surface so as to straddle the end 11a of the first release film 11 The adhesive tape 111 was bonded to the surface 21b of the release film 21 opposite to the second adhesive layer 22 side.
By doing so, a connection process was completed and the 1st conductive adhesive tape 10 and the 2nd conductive adhesive tape 20 were connected (Drawing 4).

  In addition, in the 2nd bonding process in Example 1, the surface on the opposite side to the 1st adhesion layer side of the 1st conductive substrate, and the surface on the 2nd mold release film side of the 2nd adhesion layer Are the lengths of the contact surfaces formed by bonding and the lengths in the longitudinal direction of the first conductive adhesive tape and the second conductive adhesive tape (hereinafter referred to as “wrap length”). Is 20 mm.

<Production of solar cell module model>
A set of the obtained conductive adhesive tapes is set so that the second conductive adhesive tape and the first conductive adhesive tape are delivered in this order to the reel 50 of the solar cell module manufacturing apparatus shown in FIG. did. In the manufacturing apparatus of FIG. 6, the laminating apparatus for the conductive adhesive tape has the configuration shown in FIG. Two combinations of the reel 50 and the transport roll 51 were used. The pair of laminating rolls 52 is a set.
As the long sheet 34, a PET film with ITO (average thickness 130 μm) was used. Two conductive adhesive tapes were arranged on the PET film with ITO.
In the solar cell module manufacturing apparatus shown in FIG. 6, the covering step with the sealing resin and the moisture-proof backsheet is omitted. The conditions of the heating and pressing process by the laminating apparatus were 80 ° C., 0.3 MPa, 10 mm / sec, and the sealing resin curing condition was 130 ° C. for 10 minutes. By doing so, a solar cell module model was produced.

  In the produced solar cell module model, among the two conductive adhesive tapes 30 arranged on the ITO-attached PET film 134, the first conductive adhesive tape 10 and the second conductive adhesive tape 30 The test body which has a connection location (joint) with the electroconductive adhesive tape 20 was obtained (FIG. 8).

<Evaluation>
<< Connection time >>
The time for performing the connecting step of connecting the ends of the two conductive adhesive tapes was measured. Evaluation was made according to the following evaluation criteria. The results are shown in Table 1.
In addition, the connection process was performed accurately so that the surface of the second adhesive layer was not exposed after the overlaying on the second conductive adhesive tape to be superimposed on the first conductive adhesive tape.
〔Evaluation criteria〕
◎: 30 seconds or less ○: 30 seconds or more, 1 minute or less △: 1 minute or more, 3 minutes or less ×: 3 minutes or more

<< Roll-to-roll (RtoR) system suitability >>
It was confirmed whether or not the release film could be peeled off without any problem when the bonded conductive adhesive tape was applied to a roll-to-roll (RtoR) solar cell module manufacturing method. Specifically, when the release film is peeled off from the continuous conductive adhesive tape, there is a problem that one release film does not peel off at the connection portion (joint) of the continuous conductive adhesive tape. Confirmed whether or not. The results are shown in Table 1.
When a defect occurred, it was determined that there was no aptitude ("None" in Table 1).
When no defect occurred, it was determined that there was suitability (“Yes” in Table 1).

<< Conduction resistance value >>
About the obtained test body, the conduction | electrical_connection resistance value was measured by arrangement | positioning of a terminal as shown in FIG. 8 using the digital multimeter (the Yokogawa Electric Corporation make, digital multimeter 7555). In contrast to the conduction resistance value when there is no connection point (joint) (reference), the resistance increase rate was obtained by the following formula, and the evaluation was performed according to the following evaluation criteria. The results are shown in Table 1.
Resistance value increase rate (%) = 100+ [100 × (Y−X)] / X
X: Conduction resistance value when there is no connection location (reference) Y: Conduction resistance value when there is a connection location [Evaluation criteria]
A: Resistance value increase rate (%) ≦ 100%
○: 100% <resistance value increase rate (%) ≦ 105%
X: 105% <resistance value increase rate (%)

(Examples 2 to 5)
A continuous conductive adhesive tape and a solar cell module model were produced in the same manner as in Example 1 except that the wrap length was changed to the wrap length shown in Table 1 in Example 1.
Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Examples 1 and 2)
As in Example 1, a conductive adhesive tape having a length in the longitudinal direction of about 100 m and a width of 4 mm was obtained. Two of the conductive adhesive tapes were used and their ends were connected as shown in FIG. 9 to obtain a continuous conductive adhesive tape. The wrap length was the length shown in Table 1. In FIG. 9, the code | symbol 211 shows a release film, the code | symbol 212 shows an adhesive layer, the code | symbol 213 shows an electroconductive base material, and the code | symbol 311 shows an adhesive tape.
A solar cell module model was produced in the same manner as in Example 1 by using the obtained continuous conductive adhesive tape.
Evaluation similar to Example 1 was performed. The results are shown in Table 1.

In Examples 1 to 5, the connection time was short, the roll-to-roll method was suitable, and the conduction resistance value at the connection location did not increase. Moreover, from the point of balance of connection time and conduction | electrical_connection resistance value, it has confirmed that 10 mm-50 mm were preferable for the wrap length.
On the other hand, when connecting by a method different from the connection method of the present invention, the connection time takes a little time and the roll-to-roll method is not suitable. In addition, when the wrap length was short, the conduction resistance value was low.

  The conductive adhesive tape connecting method of the present invention is suitable for manufacturing a solar cell module by a roll-to-roll method.

DESCRIPTION OF SYMBOLS 10 1st electroconductive adhesive tape 11 1st release film 11a End 11b surface of 1st release film 12 First adhesive layer 12a End of 1st adhesive layer 13 1st electroconductive base material 13b Surface 13a End of first conductive substrate 20 Second conductive adhesive tape 21 Second release film 21a End of second release film 21b Surface 22 Second adhesive layer 22a End of second adhesive layer 22b Surface 23 Second conductive substrate 23a Terminal of second conductive substrate 30 Conductive adhesive tape 31 Release film 34 Long sheet 35 Resin 36 Sealing moisture-proof back sheet 40, 50, 60, 70 , 90 Reel 42, 51, 82 Conveying roll 52, 62, 72 Laminating roll 80 Laminator device 111 Adhesive tape

Claims (7)

A method for connecting a conductive adhesive tape comprising a connecting step of connecting one end portion in a longitudinal direction of a first conductive adhesive tape and one end portion in a longitudinal direction of a second conductive adhesive tape. ,
The first conductive adhesive tape includes a metal first conductive base material, a first adhesive layer containing an adhesive, and a first release film that can be peeled off from the first adhesive layer. And in this order,
At the one end of the first conductive adhesive tape, the end of the first release film is outside the end of the first conductive adhesive tape in the longitudinal direction of the first adhesive layer. And the first adhesive layer side surface of the first release film is exposed,
The second conductive adhesive tape is a metal second conductive substrate, a second adhesive layer containing an adhesive, and a second release film that can be peeled off from the second adhesive layer. And in this order,
At the one end of the second conductive adhesive tape, the end of the second adhesive layer is outside the end of the second conductive adhesive tape in the longitudinal direction than the end of the second release film. And the second release film side surface of the second adhesive layer is exposed,
In the first connecting step, the first adhesive layer side surface of the first release film and the second adhesive layer side surface opposite to the second adhesive layer side of the first release film are bonded together. And the surface of the first conductive substrate opposite to the first adhesive layer side and the surface of the second adhesive layer on the second release film side are bonded together. A method for connecting a conductive adhesive tape comprising a second bonding process.   The surface of the first release film opposite to the first adhesive layer side and the second release film of the second release film so that the first bonding treatment straddles the end of the first release film. The connection method of the electroconductive adhesive tape of Claim 1 performed by sticking an adhesive tape on the surface on the opposite side to the adhesive layer side of 2. FIG.   In the second bonding process, the surface of the first conductive substrate opposite to the first adhesive layer side and the surface of the second adhesive layer on the second release film side are bonded together to form The length of the contact surface, and the length in the longitudinal direction of the first conductive adhesive tape and the second conductive adhesive tape is 5 mm to 100 mm. Connection method of conductive adhesive tape.   A conductive adhesive tape obtained by the method for connecting a conductive adhesive tape according to claim 1. A solar cell module manufacturing method using a roll-to-roll method,
The disposing step of disposing the conductive adhesive tape according to claim 4 from which the release film has been peeled on the electrode of the solar battery cell;
A covering step of covering the solar battery cell with a sealing resin, and further covering the sealing resin with a moisture-proof backsheet;
A pressing step of pressing the moisture-proof backsheet;
A method of manufacturing a solar cell module, comprising at least a heating step of heating the solar cell.   The method for producing a solar cell module according to claim 5, wherein in the arranging step, the release film is peeled in the order of the second release film and the first release film.   It is obtained by the manufacturing method of the solar cell module in any one of Claim 5 to 6, The solar cell module characterized by the above-mentioned.